1. Field of the Invention
The present invention relates to the field of material handling devices generally referred to as front-end loaders, and more particularly, but not by way of limitation, to a front-end loader apparatus for removing particulate material from a roadway surface or the like.
2. Discussion of Prior Art
In U.S. Pat. No. 4,139,318 entitled "A Method and Apparatus for Planing a Paved Roadway", issued Feb. 13, 1979, and assigned to the assignee of the present invention, a unique approach to the maintenance of paved roadways was introduced. That is, that patent taught the planing of roadways to remove a top portion of the roadway in a controlled fashion to expose a new planed surface having a predetermined grade and cross-slope, a practice which has now become widespread in the maintenance of paved roadway surfaces, and which forms the background to the present invention.
The process of roadway planing is described in the above-mentioned patent, but a review of that process may prove helpful to an understanding of the present invention. As a planing cutter engages a paved roadway surface, the contacted edge of the surface is pulverized by the planing cutter, and in the wake of the cutter, if the removed material is not collected, there is formed a newly exposed planed surface covered by the debris of the removed surface material, which is in a granular or particulate form.
A reclaimer assembly may be supported behind the planer cutter to receive the debris material removed by the cutter. Such a reclaimer assembly may be a floating scraper and a conveyor assembly that gathers and elevates the debris to an overhead discharge point from which the lifted debris is put into waiting trucks positioned below. However, this arrangement may not be entirely satisfactory, because practical experience has been that the progress of the planing apparatus is often interrupted while waiting for trucks to arrive. It is usually not economical to furnish the large number of removal trucks that is necessary to assure that a truck is always available for loading the material elevated by the reclaimer assembly. In addition to the small amount of time required to remove a loaded truck and to appropriately position a new truck for loading, the amount of time expended for trucks to travel to and from unloading sites must be taken into account and trucks scheduled accordingly. Since construction work is usually not manageable with absolute precision, it is frequently the case that trucks will stack up and be waiting for a load, or that there will be periods of time during which no trucks are available for receiving debris from the planing apparatus.
To alleviate the scheduling problem encountered with trucks, it would be desirable to leave the debris material on the newly exposed planed surface for disposal by means separate from the planing operation. However, until the present invention, there has not been an apparatus available that is completely satisfactory for cleaning up scattered particulate material of the type left behind a roadway planing apparatus.
There are a number of prior art devices that fall in the general category of street sweepers which are effective for cleaning up dust and the like on street surfaces. A variety of such devices are taught in the patents to Beyerstedt, U.S. Pat. No. 3,186,015, "Street Sweeper"; Dear, et al., U.S. Pat. No. 2,960,708, "Road Sweeping Machines"; Martin, U.S. Pat. No. 1,452,307, "Gutter Broom Arrangement for Street Sweepers"; Finch, U.S. Pat. No. 1,085,676, "Street Sweeper"; Blaney, U.S. Pat. No. 1,209,384, "Street Sweeping Machine"; Leach, et al., U.S. Pat. No. 1,566,107, "Street Sweeping Mechanism"; Dempster, et al., U.S. Pat No. 2,725,584, "Street Sweeper"; and Gehman, et al., U.S. Pat. No. 3,186,016, "Street Sweeping Machine". These patents show various combinations of rotating transverse and gutter brooms for picking up street dirt and debris, and as such, are designed to deal with light material in relatively small quantities; none of the machines have the capability of efficiently collecting and picking up the large amount of concrete or asphaltic cuttings generated by the modern planing device discussed above.
There have been machines taught in the prior art for excavating and removing dirt, such as in the patents to Bernotas, et al., U.S. Pat. No. 3,466,765, "Self-Loading Scraper"; Crum, U.S. Pat. No. 3,805,420, "Elevating Conveyor Mechanism"; Reinhardt, U.S. Pat. No. 3,738,028, "Earth Moving Apparatuses and Process"; and Carston, U.S. Pat. No. 2,844,892, "Excavating, Loading and Carry-Off Earth Working Machine". Such excavating machines are not useful in collecting and removing particulate material laying on a paved road substrate, as such machines contemplate excavating dirt using a cutter blade assembly.
There is a line of machines available in the prior art that function to scoop up and remove windrowed or otherwise gathered material from roadway-type road surfaces. Such devices are referred to as front-end loaders, or excavating loaders. Such other machines are taught in the patents to MacDonald, U.S. Pat. No. 3,680,233, "Continuous Excavating Loader With Pivotal Discharge Conveyor", and U.S. Pat. No. 3,049,817, "Roadway Machine". Another machine of this type, useful for picking up windrowed material, is the force-feed loader manufactured as Athey Model No. 7-12 by Athey Products Corporation, Raleigh, N.C. The Athey Loader features a front mounted feeder that scoops up material and forces the material onto an inclined conveyor that elevates the material to a rear, overhead discharge point. Also known in the prior art are modifications made by some contractors of the Athey Model No. 7-12 consisting of a pair of brushes disposable on a roadway ahead of the inclined conveyor. The brushes are used to sweep particulate material scattered on the roadway into a position to be received by the conveyor.